Chironomus trabicola Shobanov, Wülker & Kiknadze, 2002 : 177

Saether, Ole A., 2004, The chironomids (Diptera, Chironomidae) described by Lundström (1915) from arctic Siberia, with a redescription of Derotanypus sibiricus (Kruglova & Chernovskii), Zootaxa 595, pp. 1-35 : 7-8

Chironomus trabicola Shobanov, Wülker & Kiknadze, 2002: 177

( Figs. 3, 4, 10 )

Chironomus niveipennis F. sensu Lundström (1915: 6), not Fabricius, 1805: 42.

Material examined. RUSSIA: New Siberian Islands, west coast, 1 ď, 1Ψ, 12 vi 1903 [16 (3) vi 17 (4) vii 1903 in Lundström], M. I. Brussnew; Chara­Ullach Mts., 1 Ψ, 28 vi 1902 [5 viii (22 vii) 1902 in Lundström], M. I. Brussnew.

MALE IMAGO

The male has been described by Shobanov et al. (2002). Their description can be supplemented with:

Head. Clypeus with about 110 setae. Frontal tubercle ( Fig. 4 ) conspicuous, 56 m long, 17 m wide, with some conspicuously long microtrichia with distinct bases; frons with dense microtrichia forming a fur­like covering.

Thorax. Dorsocentrals about 70, prealars 17. Scutellum with about 130 setae.

Wing. Brachiolum with 5 setae, R with 28 setae, R1 with 1 seta, other veins bare. Squama with about 40 setae.

FEMALE IMAGO (n = 1–2)

Total length 8.22–8.69 mm. Wing length 4.73–5.10 mm. Total length/wing length 1.70–1.74. Wing length/length of profemur 3.13. Thorax, abdomen brown, legs brownish black.

Head. AR 0.57. Flagellomere lengths (in m): 191, 128, 135, 128, 330; and 229, 139, 150, 116, lost. Dorsal interocular distance 191–263 m, ventral interocular distance 308– 341 m. Frontal tubercle ( Fig. 3 ) 38–56 m high, 17–19 m wide, with conspicuous microtrichia as in male. Frons with long and dense microtrichia. Temporal setae 44–47, consisting of 15 inner verticals, 18–22 outer verticals and 10–11 postorbitals. Clypeus with 60–63 setae. Tentorium 244–266 m long, 60–71 m wide; stipes 244–278 m long, 79– 124 m wide. Palpomere lengths (in m): 79–86, 94–101, 296–300, 263–330, 394–428. Third palpomere with 6 lanceolate, 30 m long sensilla clavata.

Thorax. Antepronotal setae apparently absent. Acrostichals not countable, dorsocentrals 71–74, prealars 12–15, supraalars 2. Scutellum with about 100–120 setae.

Wing. VR 1.04. Brachiolum with 4 setae, R with 25–33, R1 with 6–9, R4+5 with about 30 setae, other veins bare. Squama with about 50 setae.

Legs. Scale of front tibia 68 m long, spurs of mid tibia 75 and 60 m long including combs, spurs of hind tibia 83–90 and 75–79 m long including combs. Width at apex of front to hind tibiae (in m) as 124, 120–146,120–150. Sensilla chaetica about 55–95 on ta1 of mid leg, about 66–96 on ta1 of hind leg. Lengths (in m) and proportions of legs: Abdomen. Tergite VIII with 75–78 setae. Sternite VIII with 94–95 median setae and 10–12 setae to each side.

Genitalia ( Fig. 10 ). Gonocoxite with 0–3 setae. Tergite IX with about 55–75 setae. Segment X with 24–30 setae. Ventrolateral lobe of gonapophysis VIII conspicuously wide. Cercus 309–330 µm long. Seminal capsule 188–221 µm long, 113–150 µm wide. Notum 270–319 µm long.

Remarks

Chironomus niveipennis Fabricius, 1805 is currently considered a synonym of C. pilicornis ( Fabricius, 1787) . The present specimens, however, do not key to C. pilicornis , for instance in Lindeberg & Wiederholm (1979), e.g. the male anal point is tapering from base to tip, not basally constricted. The female differs from the other species described here by having a much wider ventrolateral lobe. Among the limited number of Chironomus species with adequately described female genitalia only C. entis Shobanov ( Saether 1977, fig 81 D, E, as C. plumosus (L.) fa. semireductus Lenz) and C. bonus Shilova & Djvarsheisvili (Rodova 1978, fig. 9) appear to have equally wide ventrolateral lobe. Chironomus trabicola was described from the Lena delta in Russia (74° N latitude, Shobanov et al. 2002).

Figures

FIGURES 1 – 10. Chironomus (Chironomus) spp., imagines, 1: C. lundstroemi sp. n., hypopygium, 2 – 6: frontal tubercles and frons, 2: C. lundstroemi sp. n., female, 3 – 4: C. trabicola Shobanov, Wülker & Kiknadze, female and male, 5: C.? lugubris Zetterstedt, female, 6: C. flavoviridis Lundström, female, 7 – 10: female genitalia, apodeme lobe (shown separately), dorsomesal and ventrolateral lobes, 7: C. lundstroemi sp. n., 8: C.? lugubris Zetterstedt, 9: C. flavoviridis Lundström, 10: C. trabicola Shobanov, Wülker & Kiknadze.